Present invention relates to wrenches and more particularly to wrenches that are driven by a power unit.
Wrenches have been used for many years in driving bolts and nuts in a variety of mechanical applications. For more than a hundred years wrenches have been available for example in hexagonal shapes. Early wrenches were formed by bending of sheet metal into a hexagonal shape. These wrenches were driven by an integral lever.
Wrenches have been improved over the past century and are now available in a wide variety of types. The types include socket wrenches, open end wrenches, box wrenches, Crescent wrenches, pipe wrenches and a wide variety of others. In the early part of the century, wrenches were hand driven. In other words, the wrench included a handle portion to be grasped by the user""s hands. The user""s hand rotates the handle around the portion of the wrench which grips the bolt, screw or the like. The longer the wrench handle, the greater the power that is applied to the bolt.
Later developments of the wrench found power driving mechanism. Early in this development the power driver was an electrical drill power unit in which a socket was mounted. Later pneumatic and hydraulic power drivers were developed for driving the wrench. Screw drivers followed a similar development pattern. Early screwdrivers were hand driven. More recently power driven screwdrivers and bit attachments have been developed.
Eye bolts provide a unique situation since they are not easily grasped by a wrench. Historically, eye bolts have been driven by insertion of a short bar through the eye of the bolt. The bar is then moved to rotate the eye bolt until the eye bolt is secured in place. Any of a variety of short bars have been used in the past. For example, the shaft of a screwdriver was often used as the bar. Use of a bar for rotating the eye bolt is slow and clumsy. This is not a serious problem if a very limited number of eye bolts are being secured in place in a given application. However it becomes slow, tedious, and particularly clumsy if a large number of eye bolts are inserted in place. There has long been a need for a wrench adapted for use with eye bolts.
The present invention overcomes this long standing problem by providing a wrench that is adapted for use with an eye bolt. The present eye bolt wrench may be used to insert a large number of eye bolts in place using any of various conventional power driving devices such as electrical screwdrivers, electrical drills, pneumatic rotational drivers, hydraulic rotational drivers and the like.
The present invention relates to the wrench for engaging eye bolts. The term eye bolts refers to a support mechanism that includes a threaded shaft and integral loop. The threaded shaft may be frustaconically shaped, e.g., the shaft decreases in diameter terminating in a point. Alternatively, the eye bolt may include a threaded shaft that is of a constant diameter. The eye bolt may be screwed into a cavity such as a cavity in a concrete wall. The eye bolt may create its own cavity as the eye bolt is screwed into a structure, such as screwed into a piece of lumber.
The present wrench includes a shaft and a cup. The shaft may be releasibly engaged with the cup such that the shaft is rotationally locked with respect to the cup and yet disengageable when one wishes to use a different sized cup with the shaft. Alternatively, the shaft and cup may be integral, e.g., cast as one piece. The cup may define an elongated cavity. In other words, the cavity may be semicircular in vertical cross section from one plan view. The cavity may be of a narrower semicircular shape in a cross sectional view from a ninety degree plan view. This creates a cavity adapted for reception of a portion of the eye portion of the eye bolt. The wrench may be driven by an electrically powered screwdriver or any other suitable rotational driving device such as a hydraulic driver or pneumatic driver.